Dear listers, I am trying to assess variance components for a nested, mixed-effects model. I think I got an answer that make sense from R, but I have a warning message and I wanted to check that what I am looking at is actually what I need:
my data are organized as transects within stations, stations within habitats, habitats within lagoons. lagoons: random, habitats: fixed the question is: how much variation is due to lagoons? habitats? lagoons*habitat? transects? Here is my code: res <- aov(COVER ~ HABITAT + Error(HABITAT+LAGOON+LAGOON/HABITAT), data=cov) summary(res) and I get Sum Sq for each to calculate variance components: Error: STRATE Df Sum Sq Mean Sq STRATE 5 4493.1 898.6 Error: ATOLL Df Sum Sq Mean Sq F value Pr(>F) Residuals 5 3340.5 668.1 Error: STRATE:ATOLL Df Sum Sq Mean Sq F value Pr(>F) Residuals 18 2442.71 135.71 Error: Within Df Sum Sq Mean Sq F value Pr(>F) Residuals 145 6422.0 44.3 My error message seems to come from the LAGOON/HABITAT, the Error is computed. Warning message: Error() model is singular in: aov(COVER ~ HABITAT + Error(HABITAT+LAGOON+LAGOON/HABITAT), data=cov), THANKS !!! eric Eric Pante ---------------------------------------------------------------- College of Charleston, Grice Marine Laboratory 205 Fort Johnson Road, Charleston SC 29412 Phone: 843-953-9190 (lab) -9200 (main office) ---------------------------------------------------------------- "On ne force pas la curiosite, on l'eveille ..." Daniel Pennac ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html